Method and apparatus for communicating with one of plural devices associated with a single telephone number during a disaster and disaster recovery

ABSTRACT

A system for (and a method of) selectively establishing communication with one of plural devices associated with a single telephone number during a disaster or disaster recovery period. In a preferred embodiment, the system includes two wireless connection units, each connected between a respective private branch exchange (PBX) network and a public switched telephone network. Each wireless connection unit preferably serves as a gateway between its respective PBX network and one or more remote communication devices. The wireless connection units replicate each others databases. In the event of a disaster that destroys or renders one of the wireless connect/PBX networks inoperable, telephone calls destined for the inoperable network are seamlessly routed to the operable wireless connect/PBX network. Since the operable wireless connection unit contains information for both networks, inbound, outbound and extension to extension calls for each network can be handled despite the disaster.

[0001] This application is a continuation-in-part (C-I-P) of applicationSer. No. 09/593,543 filed on Jun. 14, 2000, which claims priority fromprovisional application Ser. No. 60/139,498, filed Jun. 14, 1999, andNo. 60/185,070 filed Feb. 25, 2000, all of which are hereby incorporatedby reference in their entirety.

BACKGROUND

[0002] It has become relatively common for individuals to possess anumber of different devices through which they communicate. For example,a person may have a home telephone, a wireless telephone, a pager and anoffice telephone. As the population becomes increasingly mobile, makingcontact with a person through one of these communication devices hasbecome more difficult.

[0003] Call forwarding is one method of addressing this problem. Certaintelephone systems allow users to enter another number to which a call isforwarded if not answered by a specified number of rings. This shouldallow an individual with multiple telephone devices to forward the callto such devices until the telephone at which the individual is locatedfinally rings. However, if several telephones are involved, thisapproach becomes complicated. Moreover, it requires the calling party toremain on the line for a significant period of time if the call is to beforwarded multiple times. Furthermore, it is necessary that callforwarding capabilities exist on each of the individual's telephones. Inaddition, this approach requires that all telephones involved bereprogrammed each time an individual desires to initiate callforwarding. A significant drawback to this forwarding strategy is that,in each leg of the forwarded call, the calling party is terminated onthe last device or network in the chain. It follows that the finalnumber in the forwarding scheme is responsible for all availableenhanced services or voice mail available to the caller. Accordingly,although a call may have been initially placed to an office telephoneequipped with voice mail and/or operator assist, all such enhancedservices of the corporate network are lost once the call is forwardedoff the corporate PBX (e.g., to the user's wireless telephone).

[0004] Travel can also exacerbate the difficulty of establishingcommunication with an individual having access to multiple telephonedevices. Upon checking into a hotel, the telephone in a traveler's hotelroom becomes available as yet another potential means of contact.Unfortunately, this forces a calling party to decide whether to attemptto contact the traveler through his or her room telephone or othertelephone device (e.g., wireless telephone or pager). If the travelerdoes not answer the called telephone, the calling party then must decidewhether to leave a message (unaware of when, or if, the message will beretrieved) or instead attempt to reach the traveler via his or her othertelephone. Likewise, if the traveler is expecting an important call butis unsure whether it will be placed to his room telephone or wirelesstelephone, the traveler may feel compelled to remain within his roomuntil the call has been received. In addition, if the traveler'swireless telephone does not support certain types of long distance calls(e.g., to various foreign countries), the traveler may be able to placecertain types of calls only from his or her hotel room.

[0005] The office telephone is the primary point of contact of mostbusiness people. Typically, corporations invest significantly in theiroffice telephone infrastructure, which often includes voice mail, pagingand unified messaging systems. In addition, most corporations havenegotiated contracts with their telephone carriers (e.g., local and longdistance carriers) to ensure they obtain the lowest possible rates forcalls placed via their corporate network. However, because the corporateworkforce is becoming increasingly mobile, more business people areusing wireless telephones to conduct their business when they are out ofthe office. This has resulted in corporations spending a larger portionof their telecommunications budget on wireless communications, with farless favorable negotiated rates than the rates of their corporatenetwork. In addition, wireless communication systems often lack theenhanced conveniences (e.g., interoffice voice mail, direct extensiondialing, etc.) that corporate users have come to expect in the officeenvironment.

[0006] A solution to the aforementioned problems would be to allowwireless telephony devices (e.g., wireless telephones or pagers) toaccess an office telephone system as though they were desktop telephonesconnected to the company's PBX. It is desirable to incorporate wirelessdevices into the PBX network so that users may place and receivetelephone calls using the office PBX telephone system even though theyare at a remote location (e.g., out of the office). This would allow theenhanced conveniences of today's PBX networks (e.g., interoffice voicemail, direct extension dialing, etc.) to be available on wirelessdevices—something which is desperately needed in today's society.

[0007] There have been recent attempts to incorporate wirelesstelephones into PBX networks. One system provided by Ericsson, requiresthe creation of a mini-cellular network within the confines of theenterprise. A cellular switching unit, unique wireless telephones and anauxiliary server are required to route inbound telephone calls to awireless handset serving as a remote office telephone.

[0008] An in-building wireless system has been proposed by NortelNetworks. This system requires the wiring of pico-cells throughout theenterprise's building. The system routes inbound telephone calls tospecialized wireless telephones serving as additional office PBXtelephones. The wireless telephones cannot be used as conventionalstandard wireless telephones until they leave the premises.

[0009] These systems allow inbound calls to be routed to an officetelephone and a wireless telephone, but they are not without theirshortcomings. For example, each system requires specialized cellularequipment and wireless handsets. Moreover, the systems only use thewireless telephones for inbound telephone calls. In addition, thesesystems cannot use the wireless telephone as a conventional wirelesstelephone (i.e., not part of the enterprise's PBX network) within thebuilding.

[0010] A major disaster causing an enterprise's office telephoneinfrastructure or PBX network to become destroyed or inoperable maypermanently damage the manner in which the enterprise communicatesinternally and with the outside world during the disaster and may alsodamage the manner in which the enterprise conducts its business afterthe disaster. For example, an enterprise, its employees and telephoneinfrastructure may be located in one or several large office buildings.The infrastructure has previously established direct inward dial (DID)telephone numbers in which the outside world may communicate with theemployees, as well as internal extensions by which the employees maycommunicate with each other. All of the DID telephone numbers,extensions, and voice mail boxes, etc. likely will be wiped out if thePBX network gets destroyed (e.g., if the building housing the PBXnetwork is destroyed due to terrorists, natural disaster or otheroccurrence).

[0011] Currently, in the wake of such a disaster, there is no way forthe telephone company to reroute all of the enterprise's DID telephonenumbers to another telephone infrastructure or PBX network. This meansthat during the disaster there will be no way for the outside world tocommunicate with the enterprise, hampering disaster recovery efforts.Presuming that the enterprise can continue to operate after such adisaster (e.g., relocate to another location, such as another branch ofthe enterprise), future business still will be hampered because theoutside world can no longer reach the enterprise via the thousands ofpreviously established DID numbers. At best, the DID numbers can beterminated at voice mail boxes, but the employees will never be able toreceive calls at the numbers again. Moreover, the destruction of the PBXnetwork results in the destruction of the enterprise's internalextensions, which impedes the employees' ability to contact each otherand perform daily operations. These problems will occur whether theenterprise's PBX network incorporates wireless telephones or not. Thus,there is a desire and need for a telecommunications system that canallow communications to continue through the enterprise's DID numbersand internal extensions during a disaster and during disaster recovery.

SUMMARY

[0012] A system for (and a method of) selectively establishingcommunication with one of plural devices associated with a singletelephone number during a disaster or disaster recovery period. In apreferred embodiment, the system includes two wireless connection units,each connected between a respective private branch exchange (PBX)network and a public switched telephone network. Each wirelessconnection unit preferably serves as a gateway between its respectivePBX network and one or more remote communication devices. The wirelessconnection units replicate each others databases. In the event of adisaster that destroys or renders one of the wireless connect/PBXnetworks inoperable, telephone calls destined for the inoperable networkare seamlessly routed to the operable wireless connect/PBX network.Since the operable wireless connection unit contains information forboth networks, inbound, outbound and extension to extension calls foreach network can be handled despite the disaster.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 illustrates an exemplary telecommunication systemconstructed in accordance with an embodiment of the invention.

[0014]FIG. 2. illustrates a wireless connection unit in accordance withan embodiment of the invention.

[0015]FIG. 3 illustrates in flowchart form exemplary inboundstation-to-station call processing performed in accordance with anembodiment of the invention.

[0016]FIG. 4 illustrates in flowchart form exemplary inbound directinward dialing (DID) call processing performed in accordance with anembodiment of the invention.

[0017]FIG. 5 illustrates in flowchart form exemplary remote outboundcall processing performed in accordance with an embodiment of theinvention.

[0018]FIG. 6 illustrates an exemplary telecommunication systemconstructed in accordance with another embodiment of the invention.

[0019]FIG. 7 illustrates in flowchart form exemplary disaster recoveryprocessing performed in accordance with an embodiment of the invention.

[0020]FIG. 8 illustrates in flowchart form exemplary databasereplication processing performed in accordance with an embodiment of theinvention.

[0021]FIG. 9 illustrates in flowchart form exemplary remote outboundcall processing performed in accordance with another embodiment of theinvention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0022] Preferred embodiments and applications of the invention will nowbe described. Other embodiments may be realized and structural orlogical changes may be made to the disclosed embodiments withoutdeparting from the spirit or scope of the invention. Although thepreferred embodiments disclosed herein have been particularly describedas applied to a business or office environment, it should be readilyapparent that the invention may be embodied for any use or applicationhaving the same or similar problems.

[0023] The invention is more fully understood with reference to thepreferred embodiments depicted in FIGS. 1-5. A first exemplaryembodiment of the invention is discussed and illustrated with referenceto its implementation within an office building or other enterpriseestablishment. In an office, for example, personnel are assigned tooffices (or cubicles) with each office having an associated telephone.The office telephones are typically connected to a PBX, exchange, orother call processing infrastructure. The PBX allows each officetelephone to have its own telephone extension and a direct inward dial(DID) telephone number. As known in the art, a telephone extension istypically a three or four digit telephone number wherestation-to-station (i.e., office-to-office) calls can be placed bydialing the three or four digit extension. This is commonly referred toas direct extension dialing. As also known in the art, a DID telephonenumber allows external calls (i.e., calls initiated outside of theoffice PBX) to be placed directly to the office telephone.

[0024] The invention is not to be limited to any particular environment.The invention may be implemented, for example, in a hotel, boardinghouse, dormitory, apartment, or other commercial or residentialestablishment, where individuals are assigned to a unique extension orDID telephone number. The term “office” as used herein encompasses asingular room or space within a business or other enterprise, or a hotelroom or similar facility. The term “user” as used herein encompassesoffice personnel, hotel guests or other individuals associated with atelephone extension and DID telephone number.

[0025]FIG. 1 illustrates an exemplary telecommunication system 10constructed in accordance with an embodiment of the invention. As willbe discussed below, the system 10 provides for a fill integration ofremote telephony devices, such as a wireless telephone 70, into anoffice or hotel PBX or other communications network. In doing so, thesystem 10 can selectively establish communications with one of aplurality of telephony devices associated with a particular telephoneextension or DID telephone number. Moreover, the system 10 will allowremote devices such as the wireless telephone 70 to perform as a fillyfunctional standard office telephone 12 a, 12 b for both inbound andoutbound communications. That is, a remote device will be able to usefeatures of the office network (e.g., direct extension dialing,corporate dialing plan, etc.) even though the device is not within theconfines of the office or not directly connected to the office PBX. Thesystem also allows the wireless telephone 70 to operate as anindependent wireless telephone if so desired. That is, the wirelesstelephone 70 may receive calls placed to its (non-office) DID telephonenumber even though the system 10 routes PBX calls to the telephone 70.

[0026] The system 10 as particularly illustrated herein includes aconventional office PBX network 11. The PBX network 11 may include aplurality of standard telephones 12 a, 12 b respectively connected to aconventional PBX 14 via communication lines 18 a, 18 b. The PBX 14,which may be any commercially available one such as a Meridian 1 PBXproduced by Nortel Networks, is connected to a calling network such as apublic switched telephone network (PSTN) 16 by a primary rate interface(PRI) connection 20 or other suitable communication line or medium. Thestandard telephones 12 a, 12 b can be any digital or analog telephone orother communication device known in the art. As illustrated in FIG. 1,the first telephone 12 a is a digital telephone while the secondtelephone 12 b is an analog telephone. For clarity purposes only, twotelephones 12 a, 12 b are illustrated in FIG. 1, but it should beappreciated that any number or combination of telephones or othercommunication devices can be supported by the system 10. Moreover,although it is desirable to use digital telephones, the invention is notto be limited to the particular type of telephone used in the system 10.

[0027] The PBX 14 is coupled to a wireless connection unit (WC) 30. TheWC 30 is connected to the PBX 14 in this embodiment by a PRI connection22 or other suitable communication medium. The WC 30 is also connectedto a PSTN 54 by a PRI connection or other suitable digital communicationmedium. The illustrated PRI connection between the WC 30 and the PSTN 54includes a first PRI connection 32, a channel service unit (CSU) 34, anda second PRI connection 36. As known in the art, a CSU is a mechanismfor connecting a computer (or other device) to a digital medium thatallows a customer to utilize their own equipment to retime andregenerate incoming signals. It should be appreciated that theillustrated connection between the WC 30 and the PSTN 54 is one of manysuitable connections. Accordingly, the invention should not be limitedto the illustrated connection. The WC 30 is one of the mechanisms thatallows the integration of remote devices (e.g., wireless telephone 70)into the PBX network 11 and its operation will be described below inmore detail.

[0028] The WC 30 is preferably connected to a local area network (LAN)40 by an appropriate communication medium 38. Although a LAN 40 isillustrated, it should be appreciated that any other network could beused. A plurality of computers (e.g., 42 a, 42 b) may be respectivelyconnected to the LAN 40 by any appropriate communication lines 44 a, 44b. The computers 42 a, 42 b can be used by network administrators orothers to maintain WC 30 and other portions of the system 10. The LAN 40may also be connected to the Internet 50 by a suitable communicationmedium 48. A firewall 46 may be used for security purposes. In apreferred embodiment, Internet 50 can be used to allow a remoteadministration device 52 (e.g., a personal computer) to perform remoteadministration of WC 30 by office personnel or other authorized users ofthe system 10. Remote administration will allow office personnel to setuser preferences for particular telephone extensions. Thus, each officetelephone extension and associated remote device is individuallyconfigurable.

[0029] PSTN 54 is connected in this embodiment to a commercial wirelesscarrier (or other carrier not co-located with the system 10) by awireless switch 58 or other wireless carrier equipment by an appropriatecommunication medium 56. The wireless switch 58 is connected to at leastone antenna 60 (by an appropriate communication medium 62) fortransmitting signals 64 to a wireless device, such as the wirelesstelephone 70. The wireless device could also be a pager, personaldigital assistant (PDA), landline telephone, facsimile machine or otherwired/wireless communication device. It may desirable for the wirelessdevice to be capable of handling both (or either) digital and analogcommunication signals. It should be noted that any type of wirelesscommunication protocol (or a combination of different protocols), suchas TDMA, CDMA, GSM, AMPS, MSR, iDEN, WAP, etc., could be used.

[0030] It should be appreciated that the WC 30 is connected to awireless carrier through a PSTN 54 and not by unique hardware or anin-office cellular network. As a result, WC 30 only has to interfacewith conventional components, such as the PBX 14 and PSTN 54. Thus, thesystem is substantially technology independent. Moreover, specialwireless devices are not required, which allows the remote device tofunction in its conventional manner (e.g., as a separate wirelesstelephone) and as part of the PBX network 11 (if so desired).

[0031] The WC 30 and the PBX 14 may also be connected to anaccounting/billing system 80. The billing system 80 may also beconnected to the LAN 40 so that system administrators may access thecontents of the billing system 80. By incorporating a billing system 80into the system 10, it is possible to obtain immediate billinginformation for calls placed to/from the wireless telephone 70 or otherremote device. This immediate billing feature is not present in otherPBX or enterprise networks and is particularly useful for corporateenvironments such as law firms and government agencies, and hotelenvironments, where up to date billing information is essential.

[0032] As noted above, the WC 30 allows for the full integration ofremote devices into the PBX network 11. In a preferred embodiment, WC 30is a processor-based stand-alone unit capable of handling communicationsdirected to the PBX network 11. In a preferred embodiment, WC 30 iscomposed of one or more processors generically represented by processormodule 310 executing one or more computer programs stored in one or morememory units generically represented by memory module 320, which iscoupled to processor module 310 via bus 330, as shown in FIG. 2. Memorymodule 320 also contains one or more databases and other processingmemory used during the overall operation of system 10, as will bedescribed below. Receiving and transmitting modules 340, 350,respectively, which are coupled to processor module 310 and memorymodule 320 via bus 330, are employed to receive and transmit informationto the PBX and PSTN during call processing, as well as receiving andtransmitting other information such as administrative information.

[0033] The modules (310,320,330,340,350) making up WC 30 may beimplemented using any known hardware or software devices. For example,in one embodiment, workload performed by receiving and transmittingmodules 340, 350, as well as some of the processing functions ofprocessor module 310 of WC 30 are implemented using one or moreconventional processor-based programmable telephony interface circuitcards used to interface WC 30 with PBX 14 and the PSTN. They areprogrammed to perform the conventional telephony services required toplace and receive calls, as well as programmed to perform the uniquecall processing functions described below. The WC 30 preferably containa database of office extension numbers (also referred to herein as PBXextensions) and DID telephone numbers associated with each existing PBXextension. The database will be stored on a computer readable storagemedium, which may be part of (e.g., in memory module 320) or connectedto the WC 30. The database may also contain a wireless connect/PBXextension (hereinafter referred to as a “WC-PBX extension”) and one ormore remote device telephone numbers associated with each PBX extension.In this embodiment, software running on the telephony cards interfaceswith the database to perform the various call processing functionsdiscussed below.

[0034] In this embodiment, the PBX 14 contains a coordinated dialingplan (CDP) steering table. The CDP steering table will be stored andretrieved from a computer readable storage medium, which may be part ofor connected to the PBX 14. The CDP steering table directs the routingof some or all PBX extensions to the WC 30 over the PRI 22 between theWC 30 and the PBX 14. In addition, the CDP steering table of the PBX 14directs the routing of all WC-PBX extensions received from the WC 30 tothe appropriate office telephone.

[0035] In accordance with a preferred embodiment of the invention,processor module 310 executes one or more programs stored in memorymodule 320 to process calls received through PBX 14 or PSTN. FIGS. 3, 4and 5 illustrate some of the basic call processing events which WC 30may be programmed to handle in accordance with exemplary embodiments ofthe invention. As illustrated in FIG. 3, when an incomingstation-to-station call (i.e., a direct extension call from one internaltelephone device to another internal device) is received by the PBX 14for an existing PBX extension (step 102), the PBX 14 looks up the PBXextension in the CDP steering table (step 104) to determine where thecall should be routed. Based on the CDP steering table the call to thePBX extension is routed to the WC 30 instead of directly to an officetelephone 12 a (step 106).

[0036] As is known in the art, the incoming call will have automaticnumber identification (ANI) and dialed number identification service(DNIS) information. The ANI identifies the telephone number of thecalling party and is traditionally used for “caller ID.” DNIS identifiesthe telephone number of the called party. The WC 30 reads the ANI/DNISinformation from the incoming call to obtain the DNIS information (step108). As noted above, the WC 30 has assigned a new WC-PBX extension toeach existing PBX extension. The WC-PBX extension, routing information,and user preferences are obtained by using the DNIS information(identifying the PBX extension) as an index into the WC 30 database(step 110). Routing information will include any additional remotetelephone numbers or voice mail box numbers, or other identificationnumbers of communication devices associated with the PBX extension.

[0037] At step 112, the WC 30 out pulses the PBX 14 through the PRIconnection 22 between the WC 30 and PBX 14 with the WC-PBX extensionobtained in step 110. This causes the PBX 14 to ring the associatedoffice telephone (e.g., telephone 12 a). At the same time (if desired),the WC 30 attempts to contact one or more alternative communicationdevices (e.g., by out dialing a remote telephone number via the PRIconnection between the WC 30 and the PSTN 54). In such embodiment, thestation-to-station call is thus routed to both the office telephone andalso to at least one remote device 70 simultaneously or substantiallysimultaneously (or as determined by the user preferences). It should benoted that the illustrated processing 100 is one example of how anincoming station-to-station call may be handled. Individual userpreferences may alter the way the call is processed. It should be notedthat in a preferred embodiment, the WC 30 is dialing the remote devicetelephone number and out pulsing the PBX 14 with the WC-PBX extension.This gives the WC 30 control over the connections to the officetelephone 12 a and the remote device 70. It should also be noted thatthe WC 30 can out dial several remote numbers, if so desired, and thatthe invention should not be limited to the dialing of one remote number.

[0038] At step 114, it is determined if the current ring count (i.e.,number of rings) exceeds the maximum ring count defined by the user.Since the WC 30 is controlling the call at this time it can track thenumber of rings. If the ring count exceeds the maximum ring count, thenthe WC 30 (if desired) forwards the call to the enterprise's voice mail(step 120). If the ring count does not exceed the maximum ring count,the WC 30 determines if the call is answered at the PBX extension (step116). The PBX 14 will issue an off-hook message to the WC 30 if theappropriate office telephone is answered. If it is determined that thecall is answered at the PBX extension, the WC 30 drops the call's pathto the remote device via the PSTN 54 and maintains the path to the PBX14 (step 122).

[0039] In a preferred embodiment, it may be desired that the call to theremote device is actually answered by the user and not by a service ofthe wireless carrier. In known systems, wireless carriers often answer acall if there is a bad connection, the wireless channels are overloadedor for other reasons (such as initiating a wireless carrier's answeringservice). When the wireless carrier answers the call in thesesituations, the call would appear to WC 30 as an “answered call” even ifthe remote user did not answer the call itself.

[0040] One way to distinguish a user answered call from a wirelessservice answered call is to prompt the user to transmit anacknowledgement signal such as a dual tone multi-frequency (DTMF) toneto the WC 30 via the keypad of the remote device. Upon detecting theanswered call, WC 30 can send a voice message instructing the user to“press 1 to complete the call or press 2 to send caller to voice mail.”If the DTMF tone is not received, then the WC 30 presumes that the callwas answered by the wireless carrier, or that the user does not want toanswer the call which the WC 30 treats as an unanswered call. If at step118, it is determined that the remote device was answered by the user,the WC 30 drops the WC-PBX extension path to the PBX and initiates theconnection between the calling party and the remote device (step 124).If the call is not answered at the remote device in step 118, processflow returns to step 114 to check whether the ring count has exceededthe maximum ring count. It should be noted that, if desired, the WC 30can forward an unanswered call to voice mail or play an interactive menuto the calling party, which allows the calling party to page the calledparty, leave a voice mail message or to transfer to an operator.

[0041] In accordance with a preferred embodiment of the invention, thedatabase of WC 30 may also contain numerous system-defined user accessrights and user modifiable preferences, which can alter the callprocessing of the invention. An office administrator may use the networkcomputers 42 a, 42 b or a remote administration device 52 to set useraccess rights and priorities (example discussed below with respect tooutbound call processing 300 illustrated in FIG. 5). The user may usethe remote administration device 52 to set numerous user preferences. Itis desirable that a Web-based or graphical user interface be used sothat the user can easily access and set user preferences. The networkcomputers 42 a, 42 b (or remote device 52) may also be used by the userif so desired.

[0042] User preferences may include how the user associated with aparticular PBX extension wants incoming calls to be routed. For example,the user can request that incoming calls be routed to the officetelephone and one or more remote devices simultaneously. The userinstead can request that an incoming call be routed to the officetelephone first, then after a user-defined number of rings, the remotedevice and eventually sent to the PBX voice mail. Alternatively, theuser can request that an incoming call be routed to the remote devicefirst, then the office telephone, and subsequently to the PBX voicemail. The user can request that all incoming calls be routed directly tothe PBX voice mail. The user can request that a menu of options beplayed to the caller so that the caller can decide how to complete thecall. The user can set separate ring counts for the office telephone andremote device. The user can set dial tone options, which allows the userto control how long a dial tone is played before a dial tone time-outoccurs. The user can adjust the time between dials. These are just a fewof the user preferences that can be stored and used by the WC 30, whichcan alter incoming and out going call processing. If the user does notchange the user preferences, or only changes a few preferences, systemdefaults are used.

[0043] When receiving an inbound DID call, call processing flow 200 (asillustrated in FIG. 4) is performed in accordance with an embodiment ofthe invention. At step 202, a DID telephone call is dialed by anexternal telephone device and received by system 10 through the PSTN. Ina preferred embodiment, PSTN has been programmed in advance to route allDID telephone numbers used by the system 10 to the WC 30. In addition,the PSTN has also been programmed to route calls incoming to the DIDtelephone number directly to the PBX 14 if the path to the WC 30 hasfailed. That is, the embodiment incorporates a failure path into thesystem 10 to ensure that a failure of the WC 30 or the PRI connectionbetween the WC 30 and the PSTN does not interrupt the operation of theoffice PBX network 11. This is possible since the steering table of theoffice PBX 14 contains the DID telephone numbers. The PBX 14 has thecapability to resolve these DID numbers. Thus, the PBX 14 can be used ifneeded to handle DID telephone calls. For purposes of this discussion,it is presumed that the WC 30 and the connection between the WC 30 andthe PSTN 54 are fully operational. Thus, at step 204, the PSTN routesthe DID call to the WC 30.

[0044] The WC 30 reads the ANI/DNIS information from the incoming DIDcall to obtain the DNIS information (step 206). The WC 30 resolves thecall by determining what WC-PBX extension is associated with thetelephone number identified by the DNIS. The WC-PBX extension, routinginformation and user preferences are obtained by the WC 30 (step 208).At step 210, the WC 30 out pulses the PBX 14 through the PRI connection22 between the WC 30 and PBX 14 with the obtained WC-PBX extension. Thiscauses the PBX 14 to ring the associated office telephone (e.g.,telephone 12 a). At the same time (if desired), the WC 30 out dials oneor more user designated remote telephone numbers via the PRI connectionsbetween the WC 30 and the PSTN 54. Therefore, the inbound DID telephonecall is routed to the office telephone and remote device simultaneously(or as determined by the user preferences). It should be noted that theillustrated processing 200 is just one example of how an incoming DIDcall may be handled.

[0045] At step 212, it is determined whether the current ring countexceeds the maximum ring count defined by the user. If the ring countexceeds the maximum ring count, then the WC 30 forwards the call to theenterprise's voice mail (step 218). If the ring count does not exceedthe maximum ring count, the WC 30 determines whether the call isanswered at the PBX extension (step 214). If it is determined that thecall is answered at the PBX extension, the WC 30 drops the call's pathto the remote device(s) via the PSTN 54 and maintains the path to thePBX 14 (step 220). If at step 214 it is determined that the call is notanswered at the PBX extension, the WC 30 determines if the call isanswered at the remote device (step 216). In a preferred embodiment, itmay be desired that the call to the remote device is actually answeredby the user and not by a service of the wireless carrier. Therefore, todistinguish a user answered call from a wireless service answered call,the WC 30 may prompt the user to transmit a DTMF tone to the WC 30 viathe remote device when the user answers the call. If the DTMF tone isnot received, then the WC 30 preferably presumes that the call wasanswered by the wireless carrier, which is interpreted by the WC 30 asan unanswered call. If at step 216 it is determined that the remotedevice was answered by the user, the WC 30 drops the path to the PBX 14and maintains the connection to the remote device (step 222). (As analternative, control and responsibility for the remainder of the callcan be left with the PSTN in order to free up PRI channels between WC 30and PSTN 54.) If the call is not answered at the remote device in step216, process returns to step 212 to check whether the ring count hasexceeded the maximum ring count.

[0046] Initially, the call processing reduces the processing load on thePBX 14, since the WC 30 (and not PBX 14) is resolving the DID telephonenumbers. This allows the PBX 14 to handle call processing for moreextensions if desired. Additionally, since the WC 30 is resolving theDID calls, the WC 30 can out pulse the PBX 14 and out dial the PSTN 54simultaneously (if desired) without waiting for the PBX 14 toprocess/resolve the call. Moreover, as noted above, redundancy isprovided by allowing the PBX network 11 to function as a standard PBX ifthe WC 30 or the link between the WC 30 and the PSTN 54 fails.

[0047] In accordance with a preferred embodiment, WC 30 allows a remotedevice such as a wireless telephone 70 to act as an office PBX telephonefor outbound telephone calls following call processing flow 300illustrated in FIG. 5. That is, a user will be able to use its wirelesstelephone (or any remote device) to make station-to-station calls as ifhe were using an office telephone directly connected to the office PBX14. From the remote device, the user will also be able to perform otherPBX functions as well. At step 302, a user places a call to the WC 30from the remote device. One way for the user to do this would be todefine a speed dial key (or sequence of keys) on the wireless telephonehandset. When the user activates the appropriate speed dial key/keys,the wireless telephone dials into the WC 30. Another way to dial intothe WC 30 would be by fixed dialing. Fixed dialing is a feature providedby the wireless carrier to always connect the wireless telephone to aparticular number or service, and, in this case, it would connect theuser to the WC 30. Any number of other methods may be used to dial intothe WC 30.

[0048] At step 304, the WC 30 reads the ANI/DNIS information receivedfrom the remote device to obtain the ANI information. The ANI identifiesthe telephone number of the wireless telephone. The WC 30 uses the ANIinformation to obtain the wireless user's access rights and userpreferences (step 306). As noted above, a user is provided with theability to set various user preferences. The enterprise itself has theability to set access rights defining what type of calls the user canplace from the remote device (e.g., local, long distance, international,station-to-station, etc.). For example, if using PRI connections betweenthe PSTN 54 and the WC 30, the PBX 14 and the WC 30, and the PBX 14 andthe PSTN 16, users can be assigned into particular access groups byassigning each user to a particular channel or group of channels of thePRI. The user assignments can be stored in a database memory withinmemory module 320 of WC 30 for access during a validation orauthentication process performed by processor module 310. In thealternative, the responsibility over the user assignments can beincorporated into PBX 14 or some other (on-site/remote) equipment.

[0049] As is known in the art, in North America and Japan, for example,each PRI contains 23 “B” channels that can be used for voicecommunications. Each B channel can be programmed with different callingcapabilities by the PBX 14. That is, some channels can be programmed forall types of calls (e.g., international, long distance, local etc.),others for long distance and local calls, while others can be programmedsolely for local or internal station-to-station calls. The channels canalso be restricted to a limited number of authorized telephone numbersas well. The programming can be determined by the enterprise. Since thechannels can be programmed with different calling capabilities, theenterprise can implement different access groups, with each groupdefining a user's remote device access.

[0050] This feature significantly limits the enterprise's remote device(e.g., wireless service) costs because user access to services can besubstantially restricted. For example, the enterprise may want deliverypersonnel to have a wireless telephone for internal dialing purposes,but may be afraid of misuse by the personnel. Implementing the aboveembodiment, the enterprise can group all wireless telephones assigned toits delivery personnel to a channel(s) restricted solely to internalcalls. Any grouping is possible. Priorities may also be assigned. A userassigned to group 1 (programmed for all calling capabilities) may begiven priority to bump a user assigned to group 2 (having less callingcapabilities) in the event that the channels assigned to group 1 arebusy. Any grouping or priority scheme can be implemented by theenterprise and is application specific.

[0051] At step 308, the WC 30 “spoofs” a dial tone to the wirelesstelephone. That is, the WC 30 generates and transmits a dial tone to thewireless telephone 70 as if the user had picked up an office telephone12 a connected to the PBX 14. In a preferred embodiment, the spoofing ofthe dial tone is achieved by the WC internally generating theappropriate tone (e.g., through software or hardware modules). The dialtone is then played to a wireless telephone as a prompt while waiting toreceive DTMF digits from the wireless user indicating the telephonenumber the user wishes to dial. At this point in the call process flow300, the user is connected to the office PBX and may access any of itsstandard features. For purposes of this illustrated embodiment, it ispresumed that the user wishes to place an outbound call at this time. Atstep 310, the user attempts to place a call and the WC 30 receives thenumber dialed by the user. At step 312, the WC 30 determines if the useris authorized to make the call. For example, the WC 30 checks the user'saccess rights, and if the user is authorized to place the call, the callis routed to the correct channel by the WC 30 based on user preferences,access rights and the channel definitions (step 314). If the user is notauthorized to place the call (i.e., the call exceeds the user's accessrights), the WC 30 performs unauthorized call processing (step 316).Unauthorized call processing may include playing a message to the userstating that the user does not have authority to place the call,disconnecting the call, or any other action desired by the enterprise.

[0052] If the user decides to place a station-to-station call, forexample, the call would appear to be an internally dialed call at thedestination office telephone. For example, if the PBX 14 uses adifferent ring for internal calls, then the internal ring would be sentto the office telephone even though the call was made by the wirelesstelephone. If the PBX 14 normally displays the PBX extension of thecalling party on the called office phone, then the PBX extension of thecalling party would be displayed on the called office telephone eventhough the call was initiated by the wireless telephone.

[0053] Many enterprises have already provided wireless communicationsdevices to their personnel. These wireless devices already have existingtelephone numbers and are external to the enterprise PBX. Since thedevices are already in use by personnel and their clients, theenterprise does not want to change their telephone numbers. There is aneed to integrate these telephone numbers into the enterprise PBX. Oneway to integrate these telephone numbers would be to forward theirunanswered calls to the PBX voice mail. This can be accomplished by theinvention whether the wireless telephone number is associated with a PBXextension or not.

[0054] For example, the enterprise can purchase additional DID telephonenumbers from the telephone company (if necessary). These additional DIDtelephone numbers are stored in the database of the WC 30 together withspecial routing instructions to route all calls directly to a user's PBXvoice mail box (or other destination as desired). The user of a wirelesstelephone can program the wireless telephone to forward unanswered callsto his associated DID telephone number. Alternatively, the user can havethe wireless carrier forward unanswered calls to the DID telephonenumber as well. This way, any unanswered call to the wireless telephonewill be forwarded to the WC 30, which resolves the DID and forwards thecall to the appropriate PBX voice mail box. Using this feature, thelikelihood is increased that the user will retrieve his messages sincehe can retrieve all of his messages through the PBX voice mail. Thisalso alleviates the need for the user to have a separate voice mailservice from the wireless carrier, which may reduce the cost of thewireless service.

[0055] The invention can be embodied in any number of differentapplications. One embodiment, for example, applies the invention to ahotel having a large number of rooms with dedicated phones lines foreach room to provide a second or “virtual phone line” without routingadditional telephone lines or other wiring to the room. Each room wouldhave the original hard-wired telephone extension that is connected tothe enterprise PBX, as well as a wireless telephone associated with thePBX extension (integrated using the invention) serving as a second orvirtual telephone line. If, for example, a guest of the hotel were usingthe hard-wired telephone line for his personal computer, he could stillmake and receive calls through the PBX with the wireless telephone.Thus, the invention allows an enterprise to double its telephone lineswithout incurring the expense of additional wiring required to install asecond line for the hotel rooms.

[0056] Another exemplary embodiment involves application of theinvention to facilitate communications in enterprises that have largeoffices located in different parts of the country. Typically, theseenterprises utilize separate PBX networks for each location. Theseparate PBX networks are often connected together using tie-lines, sothat one location can make a station-to-station call to the otherlocation. That means person A at location A can contact person B atlocation B using the PBX networks. The call will be a long distancecall, but the enterprise usually negotiates a discount rate with thetelephone carrier for dedicated, low rate long distance service.However, if person B is not in his office, person A will have to useother means to contact person B. This typically involves a call toperson B's wireless telephone, which would be an expensive long distancewireless telephone call. In this embodiment, using a WC unit in locationB, the office and wireless telephones associated with person B wouldring simultaneously. If person B answers the wireless telephone, theenterprise will not incur an expensive long distance wireless telephonecharge. Instead, since the WC unit at location B is initiating thewireless telephone call, the wireless call will only be a relativelyinexpensive local call to the pertinent wireless carrier. Moreover, ifthe enterprise can contract with the wireless carrier to get unlimitedlocal wireless telephone calls, the charge to the enterprise would beeven less. Where a WC unit is installed in both locations A and B,person A can also place the call from a wireless telephone (through theWC unit at location A) to person B, who can answer the call with awireless telephone (through the WC unit at location B). That is person Aand person B can communicate through their respective PBX networks eventhough person A and person B are away from their offices when the callis placed.

[0057]FIG. 6 illustrates an exemplary telecommunication system 400constructed in accordance with another embodiment of the invention. Aswill be explained below, the system 400 overcomes many shortcomings ofexisting enterprise PBX networks, particularly those shortcomings thatarise during and/or in disaster and disaster recovery situations. Thesystem 400 includes two telecommunication systems 10 a, 10 b constructedin accordance with the embodiments of the invention described above withreference to FIGS. 1-5. That is, each system 10 a, 10 b includes awireless connection (WC) unit 30 a, 30 b connected with a respectiveconventional office PBX 14 a, 14 b, which are in turn in connection witha PSTN 54. Both systems 10 a, 10 b may also be connected to a large areanetwork (LAN), wide area network (WAN), the Internet 50 or any othernetworked communication medium. Although FIG. 6 illustrates that thesystems 10 a, 10 b are connected to one PSTN 54, it should beappreciated that the systems 10 a, 10 b may be connected to differentand multiple PSTN's if desired.

[0058] The first system 10 a is provided at a location A while thesecond system 10 b is provided at a location B. Preferably, location Aand location B are not in the same building. In an exemplary embodiment,the first system 10 a serves as a telecommunications infrastructure foran enterprise's office provided at location A (e.g., New York office),while the second system 10 b serves as a telecommunicationsinfrastructure for the enterprise's office provided at location B (e.g.,Los Angeles office). As described above with reference to FIGS. 1-5, theWC 30 a of the first system 10 a will contain a database of officeextensions (e.g., PBX extensions) as well as DID telephone numbers,WC-PBX extensions and one or more remote device telephone numbersassociated with a respective PBX extension. The system 10 a will alsohave the ability to store user preferences to control the manner inwhich telephone calls are routed to the extensions, remote devices orvoicemail (described above). All of the telephone numbers, extensionsand user preferences stored in the WC 30 a of the first system 10 a areassociated with extensions at location A.

[0059] Similarly, the WC 30 b of the second system 10 b will contain adatabase of office extensions (e.g., PBX extensions) as well as DIDtelephone numbers, WC-PBX extensions and one or more remote devicetelephone numbers associated with a respective PBX extension. The system10 b will also have the ability to store user preferences to control themanner in which telephone calls are routed to the extensions, remotedevices or voicemail (described above). All of the telephone numbers,extensions and user preferences stored in the WC 30 b of the secondsystem 10 b are associated with extensions at location B. For the mostpart, the systems 10 a, 10 b operate as described above with referenceto FIGS. 1-5.

[0060] As part of the system's 400 disaster recovery processing, the twoWC units 30 a, 30 b, replicate each other's databases. That is, thefirst WC 30 a, servicing the extensions at location A, receives a copyof the second WC's 30 b database so that it will have a copy of locationB's PBX extensions, DID telephone numbers, WC-PBX extensions, remotedevice telephone numbers and user preferences if needed (i.e., in thecase where the WC 30 b becomes destroyed or inoperable). Likewise, thesecond WC 30 b, servicing the extensions at location B, receives a copyof the first WC's 30 a database so that it will have a copy of locationA's PBX extensions, DID telephone numbers, WC-PBX extensions, remotedevice telephone numbers and user preferences if needed (i.e., in thecase where the WC 30 a becomes destroyed or inoperable).

[0061] As will be discussed below with reference to FIG. 7, if for somereason the infrastructure of the first system 10 a becomes destroyed orinoperable, the enterprise can reroute its entire internaloffice-to-office extensions and external DID telephone numbers throughthe second system 10 b with just a simple telephone call to the PSTNhandling location A's telephone service. The second system 10 b, inparticular the second WC 30 b, then functions to route calls to theextensions at both locations A and B. No extension or DID numbers needto be changed. This is accomplished with relative ease. The PSTNhandling location A's telephone service has been programmed in advanceto route the DID telephone numbers of location A to the first WC 30 a.If WC 30 a becomes inoperable, the PSTN servicing location A needsmerely to change the telephone number from the number associated withthe first WC 30 a (part of the inoperable system) to the telephonenumber associated with the second WC 30 b (part of the operable system).

[0062] Likewise, if for some reason the infrastructure of the secondsystem 10 b becomes destroyed or inoperable, the enterprise can rerouteits entire internal office-to-office extensions and external DIDtelephone numbers through the first system 10 a with just a simpletelephone call to the PSTN handling location B's telephone service. Thefirst system 10 a, in particular the first WC 30 a functions to routecalls to the extensions of location A and location B. No extension orDID numbers need to be changed. As noted above, the PSTN has alreadybeen programmed in advance to route the DID telephone numbers oflocation B to the second WC 30 b (now part of an inoperable system).During the disaster, the PSTN servicing location B need merely changethe telephone number from the number associated with the second WC 30 b(inoperable system) to the telephone number associated with the first WC30 a (operable system).

[0063] It should be appreciated that once the PSTN reroutes the DIDtelephone numbers to the operable WC, for example, the first WC 30 a,the operable WC 30 a can perform the functions described above withrespect to FIGS. 1-5 for both enterprise systems 10 a, 10 b. Thus, usersof the inoperable WC 30 b, will be able to receive and make telephonecalls on a remote device, such as wireless telephone 70, in the mannerdescribed above. The users of both systems 10 a, 10 b still will be ableto modify user preferences through the Internet 50 or other networkconnection. For example, the user may wish to prevent the officetelephone extension from ringing since it no longer exists. Similarly,the administrator of the operable WC 30 a may choose to perform a globalchange to the rerouted user's preferences to prevent the missing officetelephone extensions from ringing, rather than having individual usersdo it themselves.

[0064] The replication of the databases (described below with referenceto FIG. 8) may be performed in any suitable manner. For example, the twoWC's 30 a, 30 b may transfer the database information over the Internet50. The database information may also be sent through the PSTN 54connection or by satellite communications via respective satelliteequipment 402 a, 402 b (FIG. 6).

[0065] By means of an example only, it is presumed that theinfrastructure of location A has been destroyed by an act of terrorismor some other disaster, which destruction includes the building housingthe system 10 a and the offices of the enterprise. During the disasterand its immediate aftermath it is desirable for the employees of theenterprise to maintain communications with the outside world (e.g., callfor help, alert loved ones that they are safe, initiate disasterrecovery steps, etc.). Since the now destroyed enterprise infrastructurecontained a WC 30 a backed up by a WC 30 b at another location, it ispossible for the employees to send and receive calls on their wirelessdevices once the system 400 initiates its disaster recovery processing.

[0066]FIG. 7 illustrates in flowchart form exemplary disaster recoveryprocessing 450 performed in accordance with an embodiment of theinvention. The first act is to detect whether there has been a disasteror other occurrence at location A that has rendered the enterprise'stelecommunication system 10 a inoperable (step 452). Once detected, thenext step performed is to alert the PSTN 54 to reroute the DID telephonenumbers for location A to the WC 30 b of the second system 10 b. Oncethe PSTN 54 completes the rerouting, which may be a matter of minutesdepending upon the number of DID telephone numbers that need to bererouted, the location A external DID telephone numbers as well as itsPBX and WC-PBX extensions, remote device telephone numbers and userpreferences will be in existence and handled by the second WC 30 b. Noneof the location A extensions or DID numbers will have been changed.Thus, the enterprise experiences minimal down time despite that factthat the disaster may still be ongoing (e.g., burning building). To theemployees and the outside world, the rerouting of the services goesunnoticed. In fact, once the disaster is over, the enterprise cancontinue to conduct internal and external communications as though theenterprise is still functioning at location A.

[0067] Essential to the aforementioned processing is the replication ofthe databases on the first and second WC's 30 a, 30 b. FIG. 8illustrates in flowchart form exemplary database replication processing500 performed in accordance with an embodiment of the invention. Forthis example, it is presumed that the first WC 30 a located at locationA is performing the processing 500. It should be appreciated, however,that both WC 30 a and WC 30 b perform the processing 500. Initially, thefirst WC 30 a checks its internal time (step 502). At step 504, thefirst WC 30 a determines if it is time to update (i.e., replicate)databases. If it is time to update the databases, the first WC 30 asends a copy of its location A database (step 506) to the WC 30 b atlocation B. It should be appreciated that the first WC 30 a will haveits main database for processing the location A telephone numbers andeither a second database or a separate portion of its main database forstoring the location B database information. Whether the WC 30 a uses asingle large database or two smaller ones is a matter of choice for theenterprise.

[0068] Once the first WC 30 a sends a copy of the location A informationto the WC 30 b, it receives a copy of the location B databaseinformation from the second WC 30 b (step 508). The information can bereceived in a message transmitted over the Internet 50 or by satellitecommunications, or it can be received by file transfer protocol (FTP) orany other networked protocol. The system 400 can be designed such thatthe information may be copied from a shared memory device or serverattached to a network connection shared by the two WC units 30 a, 30 b,or by any other method. Once the information is received, the first WC30 a updates its location B database (step 510). The first WC 30 a willthen calculate the next update time (step 512). The periodicity of thedatabase updates may be any time satisfactory to the enterprise. Itshould be appreciated that the databases can be copied in any manner andthat the invention is not limited to any particular method or means forthe replication.

[0069] It should be appreciated that the embodiments of the presentinvention are suitable for governmental purposes also. For example,presume that a governmental agency was under terrorist attack. Mostlikely, the governmental employees would be evacuated from their usuallocation. It may be necessary, however, to contact these employees orfor the employees to have access to the PBX network. If the governmentalagency was using a system 400 (FIG. 6) constructed in accordance withthe embodiments of the invention, the employees would be able to conductbusiness as usual even though they have been relocated. Mostimportantly, communications with key personnel will still be possible,which may be needed to launch counter measures against the attack.

[0070] It should be noted that the invention has been described as beingused during a disaster or as part of a disaster recovery. Although thisis a major advantage of the invention, it need not be limited to suchsituations. For example, the invention can be used during any time thereis a need to bring down one of the PBX networks (e.g., maintenance) orduring a mere power failure.

[0071] The embodiment illustrated in FIG. 6 can be used as a mechanismby a large enterprise with several offices spread throughout the worldto coordinate several PBX networks into a single pseudo-network. Inaddition, these enterprises having more than one telecommunicationsystem 10 will have multiple telephone numbers to activate outbound callprocessing from remote devices (described above with reference to FIG.5) via the multiple WC's 30. It should also be appreciated that theenterprise's system 400 can be enhanced by the “intelligent routing”feature provided by most “800 number” service providers (see below).

[0072] That is, the enterprise can obtain a single toll free callingnumber (e.g., “800 number”) so that all of its employees can dial onenumber to access their appropriate WC unit. Intelligent routing isperformed by the service provider such that the appropriate WC unit isselected based upon the location of the employee when she is placing thecall to the WC. As long as all of the WC units of the enterprise havereplicated each others databases, then it becomes possible for anemployee whose office is at location A to access the WC located atlocation B because she happens to be at the location B office. Thisallows the user to get the benefits of the location A wirelessconnect/PBX network with a local call even if she is thousands of milesaway from location A.

[0073]FIG. 9 illustrates in flowchart form exemplary remote outboundcall processing 550 performed in accordance with another embodiment ofthe invention. The processing begins when the user places a call from aremote device to a WC via the toll free calling number (step 552). Thetoll free calling service provider determines the location of the user'sremote device and selects the telephone number of the nearest WC andconnects the user to that WC (step 554). Once connected, the processing550 performs the processing 300 described above with reference to FIG.5. Thus, is it is possible to coordinate multiple WC units andtelecommunication systems for use with intelligent routing.

[0074] In a preferred embodiment, WC 30 is co-located with theenterprises' PBX 14, but may also be centrally located in a remotelocation or distributed among the many locations, or any combination ofthese arrangements.

[0075] While preferred embodiments have been specifically described andillustrated herein, it should be apparent that many modifications to theembodiments and implementations of the invention can be made withoutdeparting from the spirit or scope of the invention. For example, whilethe preferred embodiments illustrated herein have been limited to theprocessing of voice (packet or circuit switched) calls, it should bereadily apparent that any form of call (e.g., audio, video, data) may beprocessed through WC 30 to any communication device (e.g., cellularphone, pager, office/residential landline telephone, computer terminal,personal digital assistant (PDA), etc.). The individual method steps ofthe exemplary operational flows illustrated in FIGS. 2-4 may beinterchanged in order, combined, replaced or even added to withoutdeparting from the scope of the invention. Any number of differentoperations not illustrated herein may be performed utilizing theinvention.

[0076] In addition, while the illustrated embodiments have demonstratedimplementations of the invention using PBX-based communication systems,it should be readily apparent that the WC module may be connected(directly, indirectly, co-located, or remotely) with any other networkswitching device or communication system used to process calls such as acentral switching office, centrex system, or Internet server fortelephone calls made over the public switched telephone network, privatetelephone networks, or even Internet Protocol (IP) telephony networksmade over the Internet.

[0077] It should be apparent that, while only PRI lines (e.g., betweenPBX 14 and WC 30, between PBX 14 and PSTN 16) have been illustrated indiscussing preferred embodiments of the invention, these communicationlines (as well as any other communication lines or media discussedherein) may be of any form, format, or medium (e.g., PRI, Tl, OC3,electrical, optical, wired, wireless, digital, analog, etc.). Moreover,although PSTN 16, 54 are depicted as separate networks for illustrationpurposes, it should be readily apparent that a single PSTN network alonemay be used in reducing the invention to practice. It should be notedthat the WC 30 could trunk back to the PBX 14 instead of being directlyconnected to the PSTN 54. The use of a commercial wireless carriernetwork (represented by wireless switch 58 and antenna 60) as describedherein may be implemented using one or more commercial carriers usingthe same or different signaling protocols (e.g., Sprint PCS and Nextel,etc.) depending on the communication devices registered with the system.

[0078] The modules described herein such as the modules making up WC 30,as well as WC 30 and PBX 14 themselves, may be one or more hardware,software, or hybrid components residing in (or distributed among) one ormore local or remote systems. It should be readily apparent that themodules may be combined (e.g., WC 30 and PBX 14) or further separatedinto a variety of different components, sharing different resources(including processing units, memory, clock devices, software routines,etc.) as required for the particular implementation of the embodimentsdisclosed herein. Indeed, even a single general purpose computerexecuting a computer program stored on a recording medium to produce thefunctionality and any other memory devices referred to herein may beutilized to implement the illustrated embodiments. User interfacedevices utilized by in or in conjunction with WC 30 may be any deviceused to input and/or output information. The interface devices may beimplemented as a graphical user interface (GUI) containing a display orthe like, or may be a link to other user input/output devices known inthe art.

[0079] Furthermore, memory units employed by the system may be any oneor more of the known storage devices (e.g., Random Access Memory (RAM),Read Only Memory (ROM), hard disk drive (HDD), floppy drive, zip drive,compact disk-ROM, DVD, bubble memory, etc.), and may also be one or morememory devices embedded within a CPU, or shared with one or more of theother components. Accordingly, the invention is not to be seen aslimited by the foregoing description, but is only limited by the scopeof the appended claims.

What is claimed as new and desired to be protected by Letters Patent ofthe United States is:
 1. A method of operating a telecommunicationsystem including first and second enterprise telecommunication networksrespectively connected to first and second wireless connection units,said method comprising the steps of: replicating databases of the firstand second wireless connection units, the databases comprising aplurality of telephone extensions each associated with a firstcommunication device connected to the enterprise telecommunicationnetwork and a second communication device; detecting that one of thefirst and second enterprise telecommunication networks has becomeinoperable; and routing a communication destined for an extension of theinoperable enterprise telecommunication network to the wirelessconnection unit associated with and connected to the other of the firstand second enterprise telecommunication networks.
 2. The method of claim1 further comprising the steps of: identifying a dialed telephoneextension from the routed communication; using the identified extensionto retrieve a first communication device number associated with thefirst communication device and a second communication device numberassociated with the second communication device; and routing thecommunication to at least one of said first and second communicationdevice numbers.
 3. The method of claim 1, wherein the databases furthercomprise at least one user preference associated with each of theplurality of telephone extensions.
 4. The method of claim 3 furthercomprising the steps of: identifying a dialed telephone extension fromthe routed communication; using the identified extension to retrieve afirst communication device number associated with the firstcommunication device, a second communication device number associatedwith the second communication device and at least one user preference;and routing the communication to at least one of said first and secondcommunication device numbers based on the user preference.
 5. The methodof claim 3 further comprising the steps of: identifying a dialedtelephone extension from the routed communication; using the identifiedextension to retrieve a first communication device number associatedwith the first communication device, a second communication devicenumber associated with the second communication device and at least oneuser preference; and directing the routed communication in accordancewith the user preference to at least one destination communicationnumber, wherein the at least one destination communication number isselected from a group including the first and second communicationdevice numbers and a voice mailbox number.
 6. The method of claim 1,wherein said routing step comprises routing direct inbound dialedtelephone numbers associated with each extension of the inoperableenterprise telecommunication network to a telephone number associatedwith the other of the first and second enterprise telecommunicationnetworks.
 7. The method of claim 1, wherein said replicating stepcomprises: transmitting a copy of the database associated with the firstwireless connection unit to the second wireless connection unit; andreceiving at the first wireless connection unit a copy of the databaseassociated with the second wireless connection unit.
 8. The method ofclaim 7, wherein said transmitting and receiving steps are performedover a network communication medium.
 9. The method of claim 7, whereinsaid transmitting and receiving steps are performed over the Internet.10. The method of claim 7, wherein said transmitting and receiving stepsare performed by wireless communications.
 11. A method of performingdisaster recovery on a telecommunication system including first andsecond enterprise telecommunication networks respectively connected tofirst and second wireless connection units, said method comprising thesteps of: replicating databases of the first and second wirelessconnection units, the databases comprising a plurality of telephoneextensions each associated with a first communication device connectedto the enterprise telecommunication network and a wireless communicationdevice; detecting that one of the first and second enterprisetelecommunication networks has become inoperable; and routing acommunication destined for an extension of the inoperable enterprisetelecommunication network to the wireless connection unit associatedwith and connected to the other of the first and second enterprisetelecommunication networks; identifying a dialed telephone extensionfrom the routed communication; using the identified extension toretrieve a telephone number associated with the wireless communicationdevice; and directing the routed communication to the telephone numberof the wireless communication device.
 12. A method of providing accessto a telecommunication system from a wireless telephone, the systemcomprising multiple enterprise telephone networks, the method comprisingthe steps of: receiving a telephone call from the wireless telephone;determining a location of the wireless telephone; connecting thewireless telephone to one of the enterprise telephone networks based onthe location of the wireless telephone; identifying a wireless telephonenumber of the wireless telephone; using the wireless telephone number toauthenticate a user of the wireless telephone; generating a simulateddial tone; sending the simulated dial tone to the wireless telephone;providing telecommunication access to the enterprise telephone networkcommunicating with the wireless telephone based on at least one userpreference and at least one enterprise preference associated with thewireless telephone.
 13. A telecommunication system comprising: a firsttelecommunication unit connected to a first enterprise telecommunicationnetwork, said first telecommunication unit comprising: a first memorydevice comprising a first database, said first database comprising afirst plurality of telephone extensions for the first telecommunicationnetwork, each extension being associated with first and secondcommunication devices, and a first processor connected to said firstmemory device, said first processor for identifying a first telephonecall to a first dialed extension of the first telecommunication networkand routing the first telephone call to first and second communicationdevices associated with the first dialed extension; and a secondtelecommunication unit connected to a second enterprisetelecommunication network and being in communication with said firsttelecommunication unit, said second telecommunication unit comprising: asecond memory device comprising a second database, said second databasecomprising a second plurality of telephone extensions for the secondtelecommunication network, each extension being associated with thirdand fourth communication devices, and a second processor connected tosaid second memory device, said second processor for identifying asecond telephone call to a second dialed extension of the secondtelecommunication network and routing the second telephone call to thirdand fourth communication devices associated with the second dialedextension; wherein said first processor replicates and stores the seconddatabase in said first memory device and said second processorreplicates and stores the first database in said second memory device.14. The telecommunication system of claim 13, wherein said firstprocessor processes telephone calls made to extensions of the secondtelecommunication network.
 15. The telecommunication system of claim 13,wherein said second processor processes telephone calls made toextensions of the first telecommunication network.
 16. Thetelecommunication system of claim 13, wherein said first and seconddatabases further comprise at least one user preference associated witheach of said first and second plurality of telephone extensions.
 17. Thetelecommunication system of claim 16, wherein said first processorretrieves at least one user preference associated with said seconddialed extension and routes the second telephone call to third andfourth communication devices associated with the second dialed extensionbased on the at least one user preference.
 18. The telecommunicationsystem of claim 16, wherein said first processor retrieves at least oneuser preference associated with said second dialed extension and routesthe second telephone call to a destination telephone number based on theat least one user preference, wherein said destination telephone numberis selected from the group consisting of telephone numbers of said thirdand fourth communication devices associated with the second dialedextension and a voice mail box.
 19. The telecommunication system ofclaim 16, wherein said second processor retrieves at least one userpreference associated with said first dialed extension and routes thefirst telephone call to first and second communication devicesassociated with the first dialed extension based on the at least oneuser preference.
 20. The telecommunication system of claim 16, whereinsaid second processor retrieves at least one user preference associatedwith said first dialed extension and routes the first telephone call toa destination telephone number based on the at least one userpreference, wherein said destination telephone number is selected fromthe group consisting of telephone numbers of said first and secondcommunication devices associated with the first dialed extension and avoice mail box.
 21. The telecommunication system of claim 13, whereinsaid first processor replicates said second database by receiving a copyof said second database over a network communication medium.
 22. Thetelecommunication system of claim 13, wherein said first processorreplicates said second database by receiving a copy of said seconddatabase over the Internet.
 23. The telecommunication system of claim13, wherein said first processor replicates said second database byreceiving a copy of said second database by wireless communication. 24.The telecommunication system of claim 13, wherein said first processorroutes the second telephone call to a wireless device.
 25. Thetelecommunication system of claim 13, wherein said second processorroutes the first telephone call to a wireless device.
 26. Atelecommunication system comprising: means for receiving a telephonecall from a wireless device via a toll free telephone number; means fordetermining a location of the wireless device; means for connecting thewireless device to an enterprise telephone network based on the locationof the wireless device; means for identifying a wireless telephonenumber of the wireless device; means for using the wireless telephonenumber to authenticate a user of the wireless device; means forgenerating a simulated dial tone; means for sending the simulated dialtone to the wireless device; means for providing telecommunicationaccess to the enterprise telephone network communicating with thewireless device based on at least one user preference and at least oneenterprise preference associated with the wireless device.